Mechanism for manufacturing electrical conduits.



R. 0. RAHM. MECHANISM FOR MANUFACTURING ELECTRICAL GONDUITS.

APPLIOATION FILED AUG. 23, 1910.

1,017,232, Patented Feb.13,1912.

Witmmozo UNITED sTA Es PATENT OFFICE.

ROBERT C. RAHM, O'F WYOMISSING BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE AMERICAN CONDUIT MANUFACTURING COMPANY, OF PITTSBURGH, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

Patented Feb. 13, 1912.

Application filed August 23, 1910. Serial No. 578,603.

To all whom it may concern:

Be it known that I, ROBERT C. RAHM, a citizen of the United States, and a resident of the borough of Wyomissing, in the county of Berks and State of Pennsylvania, have invented certain new and useful Improvements in Mechanism for Manufacturing Electrical Conduits, of which the following is a specification.

My invention relates to machines for continuously producing composite tubing adapted for electrical conduits, from a passing strip of suitable material; and it consists in the novel combination of cooperating mechanismshereinafter fully described in connection with the accompanying drawing and specifically pointed out in the claim.

Figure 1 is a plan View of a machine embodying my invention. Fig. 2 is a longitudinal elevation of the same. Fig. 3 is a separate view of a part of the machine. Fig. 4 is a cross-sectional view of the tubing to be produced.

The machine comprises a frame-bed 2 upon which the alined cooperating mechanisms are mounted, as hereafter described; said mechanisms, as shown, being driven from a single longitudinal drive-shaft 3. The tubing to be produced comprises a tubulated strip of suitable material, as canvas, folded into tubular form with abutted longitudinal edges as indicated at 4: Fig. 4; a spiral winding of thread thereon, indicated at 5; a coating of cementitious material, as indicated at 6; and an outer wrapping of tape upon said cementitious coating'as indicated at 7.

The machine comprises a series of alined mechanisms adapted to simultaneously operate upon different portions of the passing strip so as to successively efiect the several operations required and continuously deliver the completed tubing.

The flat strip 4 enters the guide rolls 10, 11 at the left of the machine, and the completed composite tubing formed thereon is withdrawn from the machine at the opposite end by a take-off wheel 12, which is driven at a proper speed of rotation by gearing 13, 14, 15 and 16 operated by the drive shaft 3, and which ordinarily delivers to a reel, not shown.

To provide for satisfactorily effecting the I tubulating operation hereafter described, I

have found it to be practically necessary to so treat the material, preliminary to such operation, as to insure free slippage thereof upon the fixed devices over which it is drawn by the take-off mechanism. To this end I provide a reservoir 20 for lubricating material, as soapstone, and a feed-roll 21 dipping therein and cooperating with the guide rolls so as to deliver the lubricant to the passing strip as regulated by the adjustably weighted roll-lever 22. The strip 4:, after being thus lubricated, passes onward into a folding-nozzle 25 mounted on a standard 26 fixed to the machine bed 2; which nozzle folds the strip into tubular form upon a fixed mandrel 27 extending therethrough. The width of the strip is such as to bring the abutting longitudinal edges of the strip together upon the mandrel without hugging the fixed parts so as to prevent free slippage of the lubricated strip. In order to compact and retain the tubular form thus imparted to the passing strip by the fixed mandrel and folding nozzle, I provide a rotary bobbin mechanism consisting of a rotary frame 30 carrying thread bobbins 31. and tension springs 32 therefor as indicated, for exteriorly winding the tubulated strip as it leaves the fixed folding nozzle. As shown this frame 30 is mounted upon a bearing sleeve 33 fixed to a standard 34 on the frame-bed 2, and is provided with a belt pulley 35 driven from the shaft 3; the threads from the rotated bobbins passing through suitable guide-ways 36 to the longitudinally moving tubulated strip, and serving to tightly bind the latter. The thread-wound tubing, indicated at 4' in Figs.

1 and 2, in moving onward toward the takeoff, as shown, is then passed through a reservoir 40 of suitable cementitious material for the purpose of applying to the threaded surface a coating of such material; proper sized openings 11 and 42 respectively, being provided as shown in the opposite walls of the reservoir for the entering of the uncoated tubing and the exit of the coated tubing, and the coating material being'made of a proper consistency to secure the desired effect. After leaving the reservoir 4:0,.provision is made for automatically applying a covering or wrapping upon the just-applied cementitious coating of the passing tubing. The mechanism for this purpose consists as shown, of a rotary bobbin-mechanism similar to the Winding mechanism previously described; the rotary frame 45, in this case carrying tape-bobbins 4-6,being mounted upon a bearing sleeve 47 fixed to a standard 48 and being provided with a belt-pulley 4:9 driven from the shaft 3. As the coated tubing passes centrally through this mechanism, the tape from the rotary bobbins is tightly wrapped spirally upon it so as to closely adhere to the eementitious coating material and form a neat and strong covering therefor. The finished tubing passes between rollers 50 to the take-off wheel 12, and thence to a suitable reel as desired. The takeoff wheel, as shown, is provided with several different-sized tubeengaging grooves either of which may be set in line with the series of mechanisms described, to accord with the particular size of tubing provided for. hat I claim is In a tube forming machine substantially as described, the combination with stripfeeding mechanism, strip-folding mechanism, and tube-winding mechanism, of a tube take-off mechanism comprising tube guide rolls and a take-off wheel formed with different sized tube-engaging circumferential grooves, substantially as set forth.

In testimony whereof, I atfix my signature, in the presence of two witnesses.

ROBERT C. RAHM. lVitnesses:

D. M. STEWART, CALEB J. BIEBER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

